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