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