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