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