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