Save data from several related classes in the same view - Asp.Net MVC

I have a schedule class where I need to save the client data, the time, and the service that will be scheduled. However, the service is saving correctly through a selection in the DropDownList, but the client data and the Schedule are not saving in the schedule, only in the Client and Schedule classes.

How should I do it? Does it solve with a ViewModel?

Here are code for classes, controllers, and Views:

Schedule Action Create:

    [HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "ID, IDServico, IDCliente, IDHorario" )] Agenda agenda, Cliente cliente, Horario horario)
{
      if (ModelState.IsValid)
      {
           db.Clientes.Add(cliente);
           db.Horarios.Add(horario);


           db.Agendas.Add(agenda);
           db.SaveChanges();
           return RedirectToAction("Index");
      }



      ViewBag.IDServico = new SelectList(db.Servicos, "ID", "Nome", agenda.IDServico);
      ViewBag.IDCliente = new SelectList(db.Clientes, "ID", "Nome", agenda.IDCliente);
      ViewBag.IDHorario = new SelectList(db.Horarios, "ID", "Horario", agenda.IDHorario);
      return View(agenda);

}

Calendar view Create:

    @model Barbearia.Models.Agenda

@{
    ViewBag.Title = "Create";
}

<h2>Create</h2>


@using (Html.BeginForm())
{
    @Html.AntiForgeryToken()

<div class="form-horizontal">
    <h4>Agenda</h4>
    <hr />
    @Html.ValidationSummary(true, "", new { @class = "text-danger" })


    <div class="form-group">
        @Html.LabelFor(model => model.IDCliente, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Cliente.Nome, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.IDCliente, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Cliente.Telefone, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Cliente.Telefone, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Cliente.Telefone, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Cliente.Email, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Cliente.Email, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Cliente.Email, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Horario.Data, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Horario.Data, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Horario.Data, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Horario.Hora, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Horario.Hora, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Horario.Hora, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.IDServico, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.DropDownListFor(model => model.IDServico, null, htmlAttributes: new { @class = "form-control" })
            @Html.ValidationMessageFor(model => model.IDServico, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        <div class="col-md-offset-2 col-md-10">
            <input type="submit" value="Create" class="btn btn-default" />
        </div>
    </div>
</div>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

Schedule class:

'using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;

namespace Barbearia.Models
{
    public class Agenda
    {
        [Key]
        public int ID { get; set; }


        //chaves extrangeiras

        [Display(Name = "Serviços")]
        public int IDServico { get; set; }
        public virtual Servico Servico { get; set; }

        [Display(Name = "Cliente")]
        public int IDCliente { get; set; }
        public virtual Cliente Cliente { get; set; }


        public int IDHorario { get; set; }
        public virtual Horario Horario { get; set; }
    }
}'

Hug.