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