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