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