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