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