FIG. 1 is a perspective view of the painting device handle. FIG. 2 is a right side view of the painting device handle. FIG. 3 is a left side view of the painting device handle. FIG. 4 is a front view of the painting device handle. FIG. 5 is a back view of the painting device handle. FIG. 6 is a top view of the painting device handle; and, FIG. 7 is a bottom view of the painting device handle. The details shown in broken lines form no part of the claimed design.