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