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