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