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