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