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