This website has some examples. I find them too wordy but this one has great photos. It does state this is for an older verbal child. You could modify it, take the references to the other motorized objects out and just put labels or one short sentence.
http://www.child-autism-parent-cafe....restrooms.html
I like these. They are basic and you can tweak them.
http://www.polyxo.com/socialstories/