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