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