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