Considering that it has colors all over the place you'd be hard-pressed to find any automatic technique that can convert arbitrary images and make them look that way. At best I could imagine some texture overlays based on brush patterns or fractal Noises, but you'd still have to do quite a bit of manual painting and masking plus the necessary pre-processing of the image to bring out the highlights and contours.
I agree with Mylenium... there is no easy method to recreate this. It is a hand painted digital illustration by Sam Spratt, who uses custom brushes and builds the image up in layers like a traditional oil or acrylic painting. You might be able to recreate some sense of the brushstrokes by searching for tutorials on Photoshop oil paint effects, but you would still have to do a lot of manual adjustments, and it wouldn't really capture the lushness of what you're emulating. Sorry... wish I had a better quick fix answer for you.