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