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