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)(11,14)(12,20)(13,15)(16,18)(17,22)(19,24)(21,23)(25,26)(27,31)(28,37)(29,33)(30,34)(32,39)(35,36)(38,40)(1,3,5,8)(2,6,4,7)(9,11,13,18)(10,14,15,16)(12,21,22,19)(17,24,20,23)(25,27)(26,31)(28,38)(29,39)(30,35)(32,33)(34,36)(37,40)(10,15)(11,18)(17,20)(19,21)(27,35)(29,38)(31,36)(33,40) involution — undirected(1,2,5,4)(3,6,8,7)(9,11)(10,16)(12,19)(13,18)(14,15)(17,24)(20,23)(21,22)(25,28)(26,32)(27,29)(30,39)(31,40)(33,36)(34,37)(35,38)(1,2,5,4)(3,6,8,7)(9,12)(10,17)(11,19)(13,22)(14,23)(15,20)(16,24)(18,21)(25,26)(27,36)(28,32)(29,33)(30,34)(31,35)(37,39)(38,40)(1,4,5,2)(3,7,8,6)(9,10)(11,16)(12,17)(13,15)(14,18)(19,24)(20,22)(21,23)(25,29)(26,33)(27,28)(30,38)(31,37)(32,36)(34,40)(35,39)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.