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