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