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