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