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