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