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