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