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