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