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