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