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