Graphite increases the mass of the club face while maintaining the same swing weight. Because the shaft is lighter, you get to put more mass in the head. So this does not increase your swing speed, it increases the force on impact.

If you are inhibited by physical means, and your swing slows, I would suggest decreasing he stiffness of the shaft...going from a regular to a senior flex. This allows the shaft to flex at slower speeds that gets you the reflex of the shaft at impact you want to add overall speed.