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