iterate through all the instances of base class and inherited classes

I have a base class named CollidableObject and a couple of inherited classes named Player, Enemy, InertObject, etc.

I am trying to find an easy way to iterate through all the instances of them, so I initially created a list of the type CollidableObject and put all the instances of the inherited classes in there.

The thing is that because of the nature of polymorphism, when I do the following

foreach (CollidableObject CollidableObject in collidableObjects)
{
  if (CollidableObject is Player)
  {
    CollidableObject.Draw(spriteBatch, testPlayerTexture); 
  }
  // Then the same prodedure for each type of CollidableObject. 
  // Might change to switch or something.                              
}

The draw method that it calls is the generic Draw method from the CollidbaleObject base, not the overridden/new one from the Player/Enemy/inertObject class.

How do I get around this. Is there a way to iterate through a collection of objects from the same tree but maintaining their inherited type?