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