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