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