Lack of a dorsal blotch is usually enough to identify a salvini as a male. Although sometimes it is difficult to tell with young sals at a pet shop, as the spot can fade with faded coloration.
Other indications of being male, though less reliable then a lack of a dorsal blotch, are: no black spot on the edge of gill plate, more blue coloration, duller yellow, less or less solid red/orange on the abdomen. Your sal pretty much exihibits all the male traits.
With age, males tend to be deeper bodied, larger size, larger head, more up turned snout.