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