You can quilt soft lines following the flow of the design. I've done with all my bargellos. You just go diagonal across each square / rectangle following each color "line" . I used a free motion foot to keep the lines soft. Some areas you have to just follow the flow of the design rather than go square to square . I used monofilament thread so the quilting is more subtle but it really softens the design and looks great. I've done three like that. All were gifts or I'd attach a picture.
I guess it depends on what you like and how comfortable you are with quilting. It also depends on how much quilting you want. I tend to be a minimalist when it comes to a pattern like this. There's so much going on with color and movement already.
LOVE your quilt. Wonderful work.