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