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