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