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