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