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