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