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