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