So, in this case we want to start with a 1 x 1 x 1 cube, aligned to the most obviously near-planar bit on the loop, which is at the bottom. We should immediately make that editable, and working within the front orthographic and perspective viewports at the same time, you should ctrl-drag out both ends of the cube and start to rotate those polys so that it aligns in both views. Here you can see my central cube, which starts mostly planar, and the 2 sections I have extruded from either end, which now begin to match the rotation shown in the reference.
You don't have to be too exact as you do this because there will be a lot of tweaking later, but try and match the twist angles as accurately as you can.
And then it's just a question of continuing that around the loop until the ends are proximal, at which point you delete the 2 end polys, and stitch the 2 ends together.
Also, note Xray mode (basic tab) is very helpful in this mission...
CBR