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