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