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