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