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