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