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