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