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