The ornamental design for a toilet seat lifting device, as shown and described.
FIG. 1 is a perspective view of the invented toilet seat lifting device showing my new design. The portion of the drawings shown in dotted lines are for exemplary purposes only and form no part of the invented design.
FIG. 2 is a front elevational view of the invented toilet seat lifting device of FIG. 1; and,
FIG. 3 is a right side view of the invented toilet seat lifting device of FIG. 1, the left side being a mirror image except for the omission of the vertical structure.