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