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