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