I would like to draw compound contain sulfoxide(sulfinyl) that sulfur atom adopt tetrahedral geometry. Its lone pair electron play a role as one substituent. If two other substituents are different (such as Me and Phe in this example). The sulfur atom became chiral.

I have try to draw two enantiomers using Spartan 18 software. The result of geometry optimization of two enantiomers were the same and do not show chirality at sulfur atom. I don’t know how to draw sulfur atom in tetrahedral geometry to obtain R- and S-chirality.

Therefore, I would like to know the step to draw sulfur atom to obtain R- and S-chirality using Spartan 18 software or if you have other programs, could you please suggest me?