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