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