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