Any specific recommendation for soil type? I have the sphagnum mix, perlite, cactus soil and garden soil. I was going to look at purchasing potting soil if needed.

Dump out promptly, buy a general potting mix at a garden center and pot in a container that drains. And water significantly less often during the winter than in the summer, never leave sitting in water for extended periods. Also place your plant where it gets as much light as possible, short of burning.

I second Dave's advice on soil and monitoring soil moisture. Embothrium is right that a plant will need more water during the growing season and less the rest of the year, but rather than guess at the frequency you should water only when the plant needs it, which is when a dowel/skewer/disposable chopstick pushed all the way to the bottom of the pot out dry to the touch. At that point there's enough moisture inside soil particles, so don't worry about killing it; just water thoroughly and it'll be okay.

Oh, and scheffleras thrive in direct sunlight. They'll get by with bright indirect light (ie within a few feet of a window that gets good sun), but mine really took off when they got several hours of direct desert sun on the porch.

Once your plant starts growing again you'll probably want to cut it back so it will branch out, preferable around mid-summer, so come back if you want good priming advice.

And the bits you cut off the top will root quite easily to make new plants.