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