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