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