I claim the ornamental design for a drive sprocket, as shown and described.
FIG. 1 is a right oblique perspective view of a drive sprocket of my new design, showing sprocket teeth in broken lines for illustrative purposes only and forming no part of the claimed design;
FIG. 2 is a front view of the drive sprocket;
FIG. 3 is a top (edge-on) view of the drive sprocket, all other edge-on views being identical;
FIG. 4 is a back view of the drive sprocket; and,
FIG. 5 is a front view similar to FIG. 2, the only difference being the different number of teeth, which are shown for illustrative purposes only and form no part of the claimed design.