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