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