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