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