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