One vertex per element, one color per generator, with an edge from x to x·s.
(9,10)(11,19)(12,13)(14,17)(15,18)(16,22)(20,23)(21,24)(25,26,30,34)(27,36,37,32)(28,38,35,31)(29,39,40,33)(2,5)(3,7)(9,11)(10,16)(12,20)(13,21)(14,23)(15,22)(17,24)(18,19)(25,27)(26,32)(28,33)(29,31)(30,37)(34,36)(35,39)(38,40) involution — undirected(1,2)(3,6)(4,5)(7,8)(9,12,15,17)(10,13,18,14)(11,20,22,24)(16,21,19,23)(25,28,31,26,30,35,38,34)(27,33,29,32,37,39,40,36)(2,5)(6,8)(9,13,15,14)(10,17,18,12)(11,21,22,23)(16,24,19,20)(25,29,30,40)(26,33,34,39)(27,31,37,38)(28,36,35,32)(1,3,4,7)(2,6,5,8)(9,14,15,13)(10,17,18,12)(11,21,22,23)(16,20,19,24)(27,37)(29,40)(32,36)(33,39)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.