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