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