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