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