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)(11,14)(12,17)(13,18)(15,20)(16,21)(19,22)(23,24)(25,26,30,32)(27,33,36,31)(28,37,38,29)(34,35,40,39)(2,3)(6,7)(10,11)(15,17)(16,18)(22,23)(25,27)(26,31)(28,34)(29,35)(30,36)(32,33)(37,39)(38,40) involution — undirected(1,2,5,3)(4,6,8,7)(10,11)(15,17)(16,18)(22,23)(25,26,30,32)(27,31,36,33)(28,37,38,29)(34,39,40,35)(1,3,5,2)(4,7,8,6)(9,11,14,10)(12,15,20,17)(13,18,21,16)(19,22,24,23)(25,28,30,38)(26,29,32,37)(27,34,36,40)(31,35,33,39)(1,4,5,8)(2,6,3,7)(9,12,14,20)(10,15,11,17)(13,19,21,24)(16,22,18,23)(25,29)(26,28)(27,35)(30,37)(31,34)(32,38)(33,40)(36,39)(9,13)(10,16)(11,18)(12,19)(14,21)(15,22)(17,23)(20,24)(25,27)(26,31)(28,34)(29,35)(30,36)(32,33)(37,39)(38,40) 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.