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