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