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