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