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