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