Cup Storage Rack

FIG. 1 is a perspective view of the cup storage rack showing my new design; FIG. 2 is a front elevation view thereof; FIG. 3 is a rear elevation view thereof; FIG. 4 is a left side elevation view thereof; FIG. 5 is a right side elevation view thereof; FIG. 6 is a top plan view thereof; FIG. 7 is a bottom plan view thereof; and, FIG. 8 is another perspective view thereof. The broken lines throughout the drawing figures depict portions of the cup storage rack that form no part of the claimed design.