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