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