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