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