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