The ornamental design for a foraminous volleyball cover, as shown and described.
FIG. 1 is a front elevational view of a foraminous volleyball cover showing my new design, with the rear elevational view appearing the same as the front elevational view shown; and
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof; and,
FIG. 4 is a side elevational view thereof taken 90 degrees either side of the FIG. 1 front elevational view shown.