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