Absolutely, positively DO NOT PUT IT IN A PLASTIC (or nylon) BAG under any circumstances. This will cause the leather to become brittle. Store it on a quality hanger that gives good shoulder support. Zip or button it. You can simply wrap a sheet around it so it can still breathe or you can purchase a canvas garment bag at Bed Bath & Beyond or the Container Store.
If you have the space, slide it into a garment bag from a suitcase set. Then you can fold it into a drawer or hang it in the closet and still have it protected from other materials.
Hope this helps