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