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