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