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