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