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