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