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