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