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