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