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