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