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