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