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