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