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