That's probably as high as the bars go. I believe that is a threadless headset where the top tube of the fork (steerer tube) protrudes up through the frame, and the handlebar stem is clamped to the top above one or two spacers. If the spacers were above the stem, you could switch their positions, but the stem is already on top, and flipped up, instead of down. So you've already got the max height out of your equipment. If you want more height you need to replace the stem or handlebars.