The ornamental design for a cylindricalsigndisplay, as shown and described.
FIG. 1 is a front perspective view of a cylindrical sign display, showing my design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view thereof; and,
FIG. 5 is a left side elevational view thereof.
The varying stippled shading represents contrasting appearance. The broken line showing in the Figures illustrates environment and forms no part of the claimed design.