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