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