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