most driveway slabs are not as thick as a home slab and always crack and move. Remember, tile over concrete will easily break and crack with the slightest movement, perhaps even with a vehicle moving over it. Consider this first.
A good water proof thinset used as your glue troweled over the concrete will adhere the tile to the slab, then a good water proof grout used on the corners will work. Get a brown or dark grout as the grout will turn quickly being out of doors. Consider sealing the grout also, although it will not last too long being out of doors.