There is no camping allowed along the Lockett Meadow Road, except in the campground.
Freidlein Prairie Road (FR522) runs along the southern portion of the mountain and has about 15 numbered spots where dispersed camping is allowed. Most have no view, but several are set in some nice Aspen Groves. This road is accessed from the Snowbowl road, just a short way (1/2 mile?) from Highway 180. The east end of the road ends at a trailhead that connects to the Weatherford trail at its junction with the Kachina trail.
The Forest Service has a special page dedicated to camping along this road http://www.fs.fed.us/r3/coconino/recrea ... camp.shtml
Hart Prairie Road (FR151) begins about 1/2 mile past the Snowbowl road and features dispersed camping with great views, and some really nice Aspen groves. It eventually connects with FR418, which connects the loop and heads east to Hwy 89, at the junction of the Lockett Meadow Road, and Shultz Pass Road.
Speaking of Schultz Pass ... there's plenty of dispersed camping along that as well.
151, 418, and Schultz Pass all get plenty of traffic, so I would try to pick a spot that is down a spur road, not directly adjacent to one of these three.