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