(Note that there are several Deverill Roads in this area: this is the one going from Longbridge Deverill to Sutton Veny.)
I too have been back and forth along this road looking for the henge and finally found it today: a notable depression in the field, but hard to see from the road unless the light catches it - go in the late afternoon or early evening!
A henge monument on Sutton Common extant as an earthwork. The site has been surveyed by RCHME as part of the South Wiltshire project. Circa 0.2 hectares in area, it is defined by a bank circa 10 metres wide and 0.5 metres high, with an internal ditch circa 10 metres wide and 1 metre deep. Numerous hollows along its course suggest that the ditch was of segmented character. The maximum diameter is circa 80 metres, and a aingle entrance is located to the southwest. A causeway 7 metres wide connects the entrance to a sub-square central platform area circa 35 metres in diameter. The site has previously been considered a saucer barrow or a Medieval ringwork. Although seemingly atypical of henges, the form of the enclosure is not unknown among the variety of sites regarded as henges, particularly the pit-defined enclosures.
"The monument includes a henge monument set on a gentle south-east facing slope in an area of undulating chalk downland immediately east of the Wylye Valley. It comprises a central area between 30m and 33m across raised 1m above ground level. Surrounding this is a ditch, from which material was quarried during the construction of the monument, and an external bank. The ditch has been partly infilled over the years but survives to a depth of 0.5m and is c.10m across. The bank is 0.2m high and 10m wide. In the south-west portion of the ditch is a causeway c.4m across.
I must say I'm not particularly convinced by these figures but can't do any better. I was preoccupied at the time by the sheer excitement of tracking it down and taking in the feel of its location and the hillside opposite, which you can see in the photos above.
I was sadly quite thrilled to see the henge show up on Multimap's aerial photo.