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