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