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