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