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