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