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