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