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