Let G be a finite abelian group written additively with identity 0, and Ω be an inverse closed generating subset of G such that 0 / ∈ Ω. We say that Ω has the property "us" (unique summation), whenever for every 0 = g ∈ G if there are s 1 , s 2 , s 3 , s 4 ∈ Ω such that s 1 + s 2 = g = s 3 + s 4 , then we have {s 1 , s 2 } = {s 3 , s 4 }. We say that a Cayley graph Γ = Cay(G; Ω) is a us-Cayley graph, whenever Γ is an abelian Cayley graph and the generating subset Ω has the property "us". In this paper, we show that if Γ = Cay(G; Ω) is a us-Cayley graph, then Aut(Γ) = L(G) A, where and A is the group of all automorphisms θ of the group G such that θ(Ω) = Ω. Then, we explicitly determine the automorphism groups of some classes of graphs, including Möbius ladders and k-array n-cubes.