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