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