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