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