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