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