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