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