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