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