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