The ornamental design for an operating console for a printing machine, as shown and described.
FIG. 1 is a front and right side perspective view of an operating console for a printing machine showing my new design, the bottom and back being plain and unadorned with no claim being made therefor;
FIG. 2 is a top, front and right side perspective view thereof;
FIG. 3 is a right side elevational view thereof;
FIG. 4 is a left side elevational view thereof; and,
FIG. 5 is a front elevational view thereof.
The broken lines illustrate portions of the operating console for a printing machine which forms no part of the claimed design.