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