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