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