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