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