The one directly to the left (on the diagram) of where fit says 15A Power Socket should do the trick.
That will make it turn on when you turn the key to 1, 2, or ignition. I have my under dash lighting positive wire on a fuse tap there, and the ground wire going to the screw on the rim of the fuse box (black screw right behind the door.) Only the one on the right is connected to metal and grounds it, left doesn't work.
You could also tap between Washer Motor and Eng Control (though on mine that slot doesn't seem to work) or just use an add-a-circuit tap that lets you keep the original fuse intact and go in on something non-critical on ignition (like washer motor.)