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