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