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