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