摘要
Definition 1. Let G be a finite group, S G╲{1}and S<sup>-1</sup>={s<sup>-1</sup>|s∈G}=S. The Cayley graph on G with respect to S, written as Γ（S; G）, is defined as V（Γ（S; G））, E（Γ（S; G）={g, sg）|g∈G, s∈S}. If S generates G, then Γ（S; G） is connected; otherwise it consists of [G: 【S】] disjoint copies of Γ（S; 【S】）, where 【S】 denotes the subgroup of G which is generated by S.
