It's included, as Mayfly said. But, you should be aware that it's not a decal, it's a sticker. It's much too thick to bury in the finish, and it looks pretty tacky on top of the finish. So, I guess what I'm saying is don't get too excited. The best use of the thing is probably as advertisement on your rack case or car/truck rear window, if you're looking to make a statement.
They used to sell embossed metal logos that were
really nice, but they've run out of stock and haven't committed to replacing them. My understanding is they have to order them in pretty large quantities, so they've held off. They weren't terribly expensive, but they probably sold fairly slowly. A surprising number of builders will lie/cheat and put Fender decals on their headstocks, then some will do no emblem at all. Myself, I'm proud to identify the things as Warmoth parts. To me, it shows I'm a discerning builder who uses nothing but the best.
Another way you can go, though, if you have access to a laser printer is to buy
blank waterslide decal stock and make your own logo. Allows you to be pretty creative, and it's thin enough to bury in the finish.