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