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