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