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