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