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