Convert your color mode to LAB. Open curves. In both the A and the B channels move the ends 15-30 pts. The line should cross the center point. Close curves and look at the effect. Fade the curve as needed and/or use masking techniques to adjust individaul parts. It is easy to over-do this... and I may have done that on the example, and color saturation is an individual preference.

When you are happy with the result, recovnert mode to RGB (which will flattern the image).