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