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