The ornamental design for a device for retaining a towel to a chair, as shown and described.
FIG. 1 is a front elevational view of a device for retaining a towel to a chair;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is a top plan view thereof, the bottom plan view being a mirror image thereof;
FIG. 4 is a right side elevational view thereof, the left side elevational view being a mirror image thereof;
FIG. 5 is a front elevational view of a second embodiment thereof;
FIG. 6 is a rear elevational view thereof;
FIG. 7 is a top plan view thereof, the bottom plan view being a mirror image thereof; and,
FIG. 8 is a right side elevational view thereof, the left side elevational view being a mirror image thereof.
The broken line showing of a portion of a chair, a portion of a towel, and the word text is included for the purpose of illustrating environment and forms no part of the claimed design.