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