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