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