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