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