M.C.
Maybe ask them to lay down quietly for five minutes (or however long they can handle laying there..) and if they can do that they earn a quiet activity. I would offer them a book to look at, color, or something like that.
The only reason I say to have them lie down first is to hopefully give the other kids a chance to get comfortable and sleepy before seeing the others getting something to do. I would be worried they might also want to pass on the nap to color instead too.