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