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