Nort End are currently the only Championship team without a goal to their name in the league this season, and have taken just one point from their opening three games.
"I have enjoyed my time, but the time has come for a change." Shaw said.
"When you give so much time and effort for the job and seem to be everyone's fall guy, the time has come for it to stop.
"We have shareholders who have a lot more money than me, and it is time for them to see what they can do with it.
"If there are other people out there who can take this club to the next level, this is their opportunity."