Get there earlier if you can. It starts getting light as much as an hour before dawn. You may not be able to see yet, but they can. Even if this isn't the reason they go the other direction, it is worth a try. Besides, you are just gonna lay there in bed awake that last hour waiting for the alarm to go off.
I try to set my decoys in an open field close to the woods where I think they are roosted, and where they may be able to see them from the roost. After the first gobble, do a few calls to get their attention toward the decoys. If they can see them, they may fly down straight to them. Most of my turkeys have been shot before 7am.