The co-maximal subgroup graph Γ(G), of a finite group G, is a special kind of undirected graph, in which the set of vertices contains non-trivial proper subgroups of G and two distinct vertices A and U are adjacent iff AU = G. In this paper, we discuss the structures of co-maximal subgroup graphs of finite cyclic groups ℤpn, ℤp1np2m, ℤp1np2p3, ℤpn1pm2p3 and ℤp1np2mpl3 for n, m, l ∈ N, where p1, p2 and p3 are distinct prime numbers. Also, we establish the super graceful labeling of these graphs.
Kumari et al. (Wed,) studied this question.