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