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