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