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