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