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