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