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)(25,26,31,30)(27,32,29,33)(28,36,37,34)(35,40,38,39)(1,3,5,8)(2,6,4,7)(9,11)(10,16)(12,14)(13,22)(15,21)(17,24)(18,23)(19,20)(25,27,31,29)(26,32,30,33)(28,35,37,38)(34,39,36,40)(11,21)(14,24)(16,20)(18,22)(25,27,31,29)(26,33,30,32)(28,35,37,38)(34,40,36,39)(9,12)(10,13)(11,14)(15,17)(16,22)(18,20)(19,23)(21,24)(25,28)(26,34)(27,35)(29,38)(30,36)(31,37)(32,39)(33,40) 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)(25,29,31,27)(26,33,30,32)(28,35,37,38)(34,39,36,40)(9,14)(10,18)(11,12)(13,20)(15,24)(16,23)(17,21)(19,22)(25,30,31,26)(27,33,29,32)(28,36,37,34)(35,40,38,39)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.