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