The ornamental design for acupressure element for cupping device, as shown and described.
FIG. 1 is a top perspective view of the acupressure element for cupping device of my design;
FIG. 2 is a front elevational view thereof, with the rear elevational view, left side elevational view and right side elevational view being the same;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is an exploded, perspective view thereof;
FIG. 6 is a bottom perspective view thereof;
FIG. 7 is a cross-sectional view thereof showing a state of attaching my design on an individual's skin in combination with a cupping device; and,
FIG. 8 is a cross-sectional view thereof, taken along line 8-8 of FIG. 3.
The broken line showing of the cupping device and skin is included for the purpose of illustrating environmental structure and forms no part of the claimed design.