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