Graham has been ruled out due to a mild strain to his quad so Steyn comes in to earn his 13th cap in Scotland's final warm-up game before the World Cup finals.
Steyn had started Scotland's 30-27 defeat by France two weeks ago and scored two tries in that 30-27 reverse in St Etienne.
Former Glasgow hooker, Shalva Mamukashvili, who plays for Black Lion in his homeland, comes in to earn his 100th cap for Georgia.