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)(28,38)(29,34)(30,32)(31,37)(33,39)(36,40)(1,2)(3,6)(4,5)(7,8)(9,10)(11,14)(12,15)(13,16)(17,19)(18,21)(20,22)(23,24)(25,27,30,37)(26,31,32,35)(28,36,39,34)(29,33,40,38)(2,5)(6,8)(12,20)(15,22)(18,24)(21,23)(26,32)(29,40)(31,35)(33,38) involution — undirected(3,7)(6,8)(9,10)(11,17)(12,15)(13,16)(14,19)(18,23)(20,22)(21,24)(25,27)(26,31)(28,34)(29,33)(30,37)(32,35)(36,39)(38,40) involution — undirected(1,3,4,7)(2,6,5,8)(9,11,13,19)(10,14,16,17)(12,18,20,24)(15,21,22,23)(25,28)(26,33)(27,36)(29,35)(30,39)(31,40)(32,38)(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)(25,29,30,40)(26,34,32,36)(27,33,37,38)(28,35,39,31)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.