  Lin, Lu, and Yau formulated the Ricci curvature of edges in simple undirected
graphs[2]. Using their formulations, we calculate the Ricci curvatures of
Cayley graphs for the dihedral groups, the general quaternion groups, and
cyclic groups with some generating sets that are chosen so that their cardinal
numbers are less than or equal to four. For the dihedral group and the general
quaternion group, we obtained the Ricci curvatures of all edges of the Cayley
graph with generator sets consisting of the four elements that are the two
generators defining each group and their inverses elements.For the cyclic group
(Z/nZ, +), we have the Ricci curvatures of edges of the Cayley graph generating
by S_{1, k} = {+1, -1, +k, -k}.
