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