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