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