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)(25,26,30,33)(27,31,36,39)(28,29,37,32)(34,35,40,38)(1,2)(3,8)(4,6)(5,7)(10,15)(12,23)(16,19)(18,21)(25,27,30,36)(26,31,33,39)(28,34,37,40)(29,35,32,38)(1,3,5,6)(2,4,7,8)(10,15)(11,20)(17,22)(18,21)(25,28,30,37)(26,32,33,29)(27,34,36,40)(31,38,39,35)(9,11)(10,16)(12,21)(13,22)(14,20)(15,19)(17,24)(18,23)(25,28)(26,29)(27,34)(30,37)(31,35)(32,33)(36,40)(38,39) 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)(25,27)(26,31)(28,34)(29,35)(30,36)(32,38)(33,39)(37,40) involution — undirected(1,4)(2,6)(3,7)(5,8)(9,13,14,24)(10,18,15,21)(11,22,20,17)(12,16,23,19)(25,29)(26,28)(27,35)(30,32)(31,34)(33,37)(36,38)(39,40)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.