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