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