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