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