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