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