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