I'm not going to be too much help as I'm not suggesting any pattern links. I mainly use pattern leaflets I buy on eBay, as there is such a wonderful range for babies. You can also check out baby knitting books in your local library.
I'm sure others will be coming in to give you some links.
However, I knit a lot of baby garments, and just wanted to recommend you steer away from lacey, holey patterns. Besides there being a trend these days away from those designs, at least where I am, they don't suit a variegated yarn.
What would look lovely in Softee, which I have used a few times, is a simple style with lovely bands, collar and cuffs. Garter stitch or seed stitch bands look great in a variegated yarn. Then knit the rest of the sweater in stocking stitch which lets the pretty yarn make the impact. If you work a pattern stitch into the sweater it all looks too fussy, in my opinion.
Good luck. Knitting for babies is fun, and nice and quick!