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