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