Creating a soft, even light on a close subject such as this one is a challenge that is often best-met by a small softbox positioned just outside of the frame. Creating this light with an on-camera Speedlite is a challenge that is perhaps best-met with a Rogue FlashBender Softbox.
For this photo, a Canon 600EX-RT was mounted with its head in the forward position. In this position, the attached FlashBender Softbox protruded out over the end of the lens to provide a broad overhead light on the flower, creating nice soft lighting without harsh shadows.
From a compositional standpoint, I positioned the flower so that the lines of the petals would radiate into the picture from a point about 1/3 of the way into the frame from both the bottom and right. The purple color borders/frames the cream/white color.