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