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