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