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