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