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