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)(25,26,30,34)(27,32,28,36)(29,33,38,40)(31,35,37,39)(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)(26,32)(28,30)(29,37)(31,38)(33,39)(34,36)(35,40)(1,4,5,3)(2,6,7,8)(25,28,37,29,30,27,31,38)(26,32,39,40,34,36,35,33)(9,12,14,13)(10,16,17,21)(11,19,20,22)(15,23,18,24)(9,13,14,12)(10,16,17,21)(11,19,20,22)(15,24,18,23)(25,29,37,27,30,38,31,28)(26,33,39,32,34,40,35,36)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.