The ornamental design for a swingtrainingdevice for a golfer, as shown and described.
FIG. 1 is a front elevational view of a swing training device for a golfer,
showing my new and ornamental design, the rear elevational view thereof
being identical thereto;
FIG. 2 is a top plan view thereof, the bottom plan view thereof being
identical thereto;
FIG. 3 is a right end elevational view thereof, at an enlarged scale, the
left end elevational view thereof being identical thereto; and,
FIG. 4 is an enlarged fragmented isometric view of the right end portion of
the swing traing device for a golfer.