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