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