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