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