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