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)(11,15,16,13)(18,21)(19,23)(25,26,30,32,28,33,29,34)(27,31,37,39,35,38,36,40)(1,3)(2,6)(4,7)(5,8)(9,11)(10,13)(12,16)(14,15)(17,18,20,21)(19,24,23,22)(25,27)(26,31)(28,35)(29,36)(30,37)(32,39)(33,38)(34,40)(1,2,5,4)(3,6,8,7)(10,14)(13,15)(17,19,20,23)(18,22,21,24)(27,35)(31,38)(36,37)(39,40)(1,4,5,2)(3,6,8,7)(11,16)(13,15)(18,21)(22,24)(26,32)(29,30)(31,39)(33,34)(36,37)(38,40)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.