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