All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Turning your face towards the Qiblah (Ka'bah) when starting the second Tasleem is permissible as it is desirable for the praying person to start saying both Tasleems while facing the Qiblah.
Imaam An-Nawawi said in his book entitled Rawdhatu At-Taalibeen: “The perfect Tasleem is to say: “Assalaamu Alaykum Warahmatullaah” and saying the second Tasleem is a Sunnah according to the known opinion of the scholars…” When we say “two Tasleems” we mean one to the right and the other to the left. Besides, the praying person has to begin saying Tasleem while his face is towards the Qiblah and then he turns his face and he should end saying the Tasleem upon completing the turning.”
This is applicable for both Tasleems, so one should start each Tasleem while his face is in the direction of the Qiblah.
Allaah Knows best.