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