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