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