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