M.O. diagram for HF using HyperChem 5.0 - after doing a molecular mechanics geometry optimization using mm+ and a semi-empirical calculation using pm3.
 
 
M.O. diagram for HF
Expanded View

HOMO for HF - p nonbonding orbitals from the F atom.  Note the M.O. looks like a p-orbital.

LUMO for HF - s* antibonding orbital.