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)(13,14)(15,17)(16,19)(21,24)(22,23)(27,33)(31,34)(35,39)(38,40) involution — undirected(1,2,5,6)(3,7,4,8)(9,11,16,15)(10,17,19,20)(12,23,14,21)(13,22,18,24)(25,26,30,28)(27,31,33,34)(29,32,37,36)(35,38,39,40)(9,12,16,14)(10,18,19,13)(11,21,15,23)(17,22,20,24)(25,27,30,33)(26,31,28,34)(29,35,37,39)(32,38,36,40)(9,13)(10,12)(11,22)(14,19)(15,24)(16,18)(17,23)(20,21) involution — undirected(1,3,5,4)(2,7,6,8)(9,14,16,12)(10,13,19,18)(11,21,15,23)(17,22,20,24)(25,28,30,26)(27,34,33,31)(29,32,37,36)(35,38,39,40)(1,4,5,3)(2,8,6,7)(9,15,16,11)(10,17,19,20)(12,23,14,21)(13,24,18,22)(25,29)(26,32)(27,35)(28,36)(30,37)(31,38)(33,39)(34,40)A 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.