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)(11,17)(12,20)(13,14)(15,18)(16,22)(19,23)(21,24)(25,26)(27,33)(28,36)(29,34)(30,31)(32,37)(35,39)(38,40)(2,6)(3,7)(10,14)(15,17)(16,20)(23,24)(26,31)(28,37)(29,33)(35,38) involution — undirected(1,3)(2,4)(5,7)(6,8)(11,18)(15,17)(19,21)(23,24)(26,31)(27,34)(32,36)(35,38) involution — undirected(1,4)(2,3)(5,8)(6,7)(9,11,13,18)(10,15,14,17)(12,21,22,19)(16,24,20,23)(25,27)(26,29)(28,38)(30,34)(31,33)(32,40)(35,37)(36,39)(9,12)(10,16)(11,19)(13,22)(14,20)(15,23)(17,24)(18,21)(25,28)(26,32)(27,35)(29,39)(30,37)(31,36)(33,40)(34,38) involution — undirected(9,10)(11,15)(12,16)(13,14)(17,18)(19,23)(20,22)(21,24)(25,29)(26,27)(28,39)(30,33)(31,34)(32,35)(36,38)(37,40) involution — undirectedA 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.