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)(12,15)(13,22)(14,16)(17,20)(18,23)(21,24)(25,26)(27,34)(28,32)(29,38)(30,33)(31,36)(35,39)(37,40)(1,3)(2,5)(4,7)(6,8)(9,11,13,12,14,20,23,21)(10,15,18,19,16,24,22,17)(3,7)(5,8)(10,16)(15,24)(17,19)(18,22)(25,27,29,36,30,37,28,35)(26,31,32,34,33,39,38,40)(9,12,13,20,14,21,23,11)(10,17,18,15,16,19,22,24)(25,28,30,29)(26,32,33,38)(27,35,37,36)(31,34,39,40)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.