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