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