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