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)(25,26,29,32,30,34,28,33)(27,35,36,31,37,40,38,39)(1,3,5,4)(2,6,8,7)(9,10,13,16)(11,18,17,14)(12,15,20,22)(19,24,23,21)(25,27)(26,31)(28,36)(29,38)(30,37)(32,35)(33,40)(34,39)(1,3,5,4)(2,7,8,6)(9,11,13,17)(10,14,16,18)(12,19,20,23)(15,21,22,24)(25,26)(27,31)(28,32)(29,33)(30,34)(35,36)(37,39)(38,40)(1,4,5,3)(2,6,8,7)(12,20)(15,22)(19,23)(21,24)(25,28,30,29)(26,32,34,33)(27,36,37,38)(31,35,39,40)(9,12,13,20)(10,15,16,22)(11,19,17,23)(14,21,18,24)(27,37)(31,39)(35,40)(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.