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