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