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