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