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