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