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