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