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