Abstract Factory Design Pattern UML diagram

I'm trying to familiar myself with design pattern and interested to learn Abstract Factory design. I have looked at a few examples and i'm curious about the UML diagram. In Abstract Factory design, we have Abstract Factory and Abstract Product interfaces. In Abstract Factory, most examples i look at they always have member functions with return types of Abstract Product, but how come this relationship is not mentioned in UML diagram?

interface IHonda
{
    //members of abstract product
    IVehicle CreateVehicle();
    IHomeCare CreateHomeCare();
}

//Abstract Product
interface IVehicle
{
    double GetVehiclePrize(string car);
    int GetVehicleYear(string car);
    int GetVehicleRating(string car);
}

//Abstract Product
interface IHomeCare
{
    double GetHomeCarePrize(string car);
    int GetHomeCareYear(string car);
}