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