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