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