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