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