One vertex per element, one color per generator, with an edge from x to x·s.
(2,6)(3,4)(7,8)(10,14)(12,19)(15,21)(16,20)(18,23)(22,24)(25,26)(27,33)(28,36)(29,31)(30,35)(32,37)(34,40)(38,39) involution — undirected(1,2,5,7)(3,6,4,8)(9,10,13,16)(11,15,17,22)(12,20,19,14)(18,24,23,21)(28,37)(32,36)(33,40)(35,38)(3,4)(6,8)(9,11,13,17)(10,15,16,22)(12,18,19,23)(14,21,20,24)(25,27,29,34)(26,30,31,39)(28,38,37,35)(32,40,36,33)(1,3,5,4)(2,6,7,8)(11,17)(15,22)(18,23)(21,24)(26,31)(30,39)(32,36)(33,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.