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