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