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