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