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