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)(11,16)(12,22)(13,17)(14,19)(15,20)(18,23)(21,24)(25,26,31,34)(27,32,36,38)(28,35,39,40)(29,33,30,37)(1,3,5,4)(2,6,8,7)(9,11,13,20)(10,15,17,16)(12,14,21,23)(18,24,19,22)(25,27)(26,32)(28,37)(29,35)(30,40)(31,36)(33,39)(34,38)(1,3,5,4)(2,7,8,6)(9,12,23,20,13,21,14,11)(10,16,19,24,17,15,18,22)(25,28,30,38,31,39,29,32)(26,27,33,35,34,36,37,40)(1,4,5,3)(2,7,8,6)(10,17)(15,16)(18,19)(22,24)(25,29,31,30)(26,33,34,37)(27,35,36,40)(28,32,39,38)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.