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