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