It is indeed Pterostylis revoluta/Diplodium revolutum. This species is identified by the large size of the flower, light coloured labellum, a broad hood which is often a tan/white colour, and is typically found on dryer slopes. A similar species you may find on wetter slopes is D. laxum, which has longer trailing tips on its sepals, has a black labellum, and is typically quite green. D. truncatum is found in more open areas such as the interface between woodland and grassland, is much shorter, and has a blunt hood that lacks a trailing tip.