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