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