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