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