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