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