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