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