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