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