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