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