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