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