The style you've applied to the graphic has given it a great look. Yet there's more you can do, working at the level of individual shapes within the graphic. You do this on the Format tab within SmartArt Tools.
Select the shape or shapes you want to change. In the picture, we've selected several shapes.
On the Format
tab, look in the Shape Styles
group for Shape Effects
, and click its arrow.
Choose from the effects, such as the Shadow
Or choose a different bevel, a reflection, or a glow. There's also a gallery of styles, to the left of this menu, that are just for shapes.