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