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