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