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