One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(6,10)(11,12)(14,20)(18,28)(21,24)(22,26) involution — undirected(5,6)(7,11)(8,12)(9,10)(13,14,19,20)(15,24,16,21)(17,26,27,22)(18,23,28,25)(2,4)(5,7,9,8)(6,11,10,12)(13,15,19,16)(14,21,20,24)(17,23,27,25)(18,22,28,26)(1,2)(3,4)(5,8,9,7)(6,12,10,11)(13,16,19,15)(14,21,20,24)(17,23,27,25)(18,26,28,22)(13,17,19,27)(14,22,20,26)(15,25,16,23)(18,24,28,21)(13,18)(14,23)(15,22)(16,26)(17,24)(19,28)(20,25)(21,27) involution — undirectedA 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.