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