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