Sprinkle a couple pieces of bacon on the foil. This will help the sweet potatoes from sticking.
Place sweet potatoes on top and spread out evenly. It's fine if they overlap, it doesn't have to be perfect. They will all cook.
Sprinkle with cinnamon, salt, and add the rest of your bacon on top.
Slightly curl up the sides of the foil, place a smaller piece of foil on top, then lock in all the sides around the foil. Like a little package. Or packet. Whatever
Place on top rack of grill and let cook for about 25-30 minutes or until they are cooked completely through and soft. If you place it on the main part of the grill (I don't know grill terms) they will cook quicker, but will more likely burn a bit.
Recipe by PaleOMG - Paleo Recipes at http://paleomg.com/cinnamon-bacon-backyard-sweet-potatoes/