Looking at this in more detail and noting other similar orchids in the area (although few and far between, see Thelymitra nuda (Scented Sun Orchid)) this is more likely to be T.nuda?
Because of the leaf, the inflated post-anther lobe and the strongly notched apex, I believe this is T. megcalyptra. While it is suggested the petals and sepals not overlapping this does not appear very consistent. I do not see the 2 horn-like teeth of alpina either.