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