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