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