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