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