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