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