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