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