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