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