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