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