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