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