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