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