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