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