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