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)(28,36)(29,32)(30,35)(31,37)(34,38)(39,40)(1,3,4,7)(2,5,6,8)(11,18)(14,16)(19,20)(22,23)(25,26,29,32)(27,30,35,33)(28,31,37,36)(34,38,40,39)(1,2)(3,5)(4,6)(7,8)(9,11,13,18)(10,14,17,16)(12,20,21,19)(15,23,24,22)(25,26,29,32)(27,33,35,30)(28,36,37,31)(34,38,40,39)(9,12,13,21)(10,15,17,24)(11,19,18,20)(14,22,16,23)(25,27,29,35)(26,30,32,33)(28,34,37,40)(31,38,36,39)(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)(27,33)(28,31)(29,32)(30,35)(34,39)(36,37)(38,40) 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)(25,28,29,37)(26,31,32,36)(27,34,35,40)(30,38,33,39)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.