It's totally up to you! It will probably be cheapest to keep the plumbing on the wall shared with the bathroom, but you could put the washer in the lower-right corner, sink next to it, and have room for a little counter on the wall to the left of the window, for folding the stuff you bring in...

Combine the storage room and the laundry room to allow yourself a lot more flexibility. A 5 by 5 foot area doesn't leave enough room for opening doors on front loading washer and dryer at the same time if you have a sink there as well as an open hallway door. You need space for a laundry basket to take wet laundry outside, too. Download the installation manuals for the washer and dryer you chose so you can see how much space the manufacturer specifies. Then draw what's required.