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