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