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