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