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