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