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